Thermostatic control means



- July 2, 1957 R. PIERCE ETA!- THERMOSTATIC CONTROL. MEANS Filed Dec. 15, 195.4

' of the engine at this point.

United States Patent 6 i THERMOSTATIC CONTROL MEANS Earl R. Pierce, Birmingham, and George P. Ransom,

Berkley, Mich, assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application December 15, 1954, Serial No. 475,550

3 Claims. (Cl. 123-122) The present invention relates to internal combustion engines and more particularly to thermostatic control means therefor.

There are normally several accessories on the exterior of an engine which are actuated in response to the engine temperature. As an example, when an engine is operating below its normal operating temperature, the atomized fuel particles may not evaporate and/ or they may precipitate out of the charge and prevent satisfactory operation of the engine. Accordingly, it may be desirable to preheat the charge while. the engine is operating at subnormal temperaturesand thereby increase its ability to absorb the fuel. However, when the engine reaches its normal operating temperature, tendency for the fuel to precipitate is greatly reduced and it is no longer necessary to heat the charge. In fact, since heating the charge reduces the volumetric efliciency, it is desirable to eliminate such heating as soon as the engine is hot. In order to accomplish this objective, thermostatic means have been provided in heat exchanging relation with the engine for automatically actuating the heating control means. However, heretofore, it has been difficult to provide thermostatic means which will accurately sense the engine temperature and properly position the heating device in the correct position. I

his now proposed to provide thermostaticmeans which will accurately sense the engine temperature for actuating the engine accessories in response thereto. This is to be accomplished by providing a thermostat which has the temperature responsive portion disposed in the engine cooling system while another portion projects from the exterior of the engine. The projecting portion may be moved by the first portion to produce an external indication of the engine temperature and actuate an accessory in response thereto. Since the thermostat extends through a wall of the engine into the cooling system, there may be a tendency for the coolant to leak out Accordingly the mounting means for the thermostat may include a seal. Even though the thermostat projects from the engine to give an external signal this seal will not be disposed between a pair of relatively movable members and thus a hermetical seal may be provided that will prevent the leakage of coolant from the cooling system.

In the drawings:

Figure 1 is a fragmentary side view of an engine embodying the present invention, portions thereof being broken away.

Figure 2 is a fragmentary end view taken substantially along the plane of line 2-2 in Figure 1.

Figure 3 is a cross sectional view on an enlarged scale of the thermostatic control means.

Referring to the drawings in more detail, the present invention may be adapted for actuating any suitable engine accessories in response to the engine temperature. However, for the purposes of illustration, in the present instance it is particularly adapted for controlling the air intake of an engine induction system 10.

, 2,797,675 Patented July 2, 1957 This induction 10 may include an intake manifold 12 and a housing 14 mounted on the manifold 12. The intake manifold 12 which may be mounted on top of the engine 16 includes a plurality of distribution passages that communicate with the combustion chambers and a carburetor riser that communicates with the distribution passages. A so-called downdraft carburetor 18 may be mounted on this riser with a fuel pump 20 disposed adjacent thereto. A portion of the coolant jacket 22 may be provided in the manifold 12 to contain a portion of the liquid in the cooling system. The coolant in this jacket 22 may be discharged through an outlet 24 to be cooled by a radiator or other heat exchanger.

The housing 14 may be secured on top of the manifold 12 to enclose the carburetor 18 and fuel pump 20 and form an air cleaner-silencer assembly 26. A filter element 28 may be horizontally disposed in the housing to form an upper compartment 30 and a lower compartmerit 32 on the opposite sides thereof. The carburetor 18 may be disposed in the lower compartment 32 with the intake therefor extending through the filter element 28 into the upper compartment 30.

An extension 34 may be formed on one wall of the housing 14 that projects forwardly from the assembly 26 to form an intake passage 36. The present intake passage 36 terminates adjacent a portion of the exhaust system such as an exhaust crossover pipe 38 that interconnects the exhaust manifolds on the opposite sides of the engine. A shroud 40 may be disposed around the crossover pipe 38 in spaced relation to form a heating passage 42 that has the opposite ends 44 and 46 thereof open to the atmosphere. An aperture 48 may be provided in the middle of the shroud 40 to interconnect the intake passage 36 with the heating passage 42 formed by the shroud 40.

The outer end of the intake passage 36 may have a rectangular opening 50 that communicates directly with the atmosphere. A, butterfly valve 52 may be secured to a pin 53 extending across this opening 50. When the valve 52 is in the closed or vertical position, the rectangular opening 50 will be closed and the intake passage 36 will be interconnected with the heating passage 42 by the aperture 48. Thus air may flow through the opposite ends of the heating passage 42 to be heated by the exhaust gases in the crossover pipe 38 before it enters the intake passage 36. Thus the air will be preheated before the fuel is atomized therein to thereby reduce the amount of precipitation of the fuel from the charge.

When the valve 52 is in the open or horizontal position, air may flow from the atmosphere through the opening 50. The air flowing through the upper portion 54 of the opening 50 will enter the intake passage 36 while the air flowing through the lower portion 56 will enter the heating passage 42 and cool the exhaust crossover pipe 38.

Thermostatic means 58 may be provided for automatically positioning the valve 52 in response to engine temperature. In the present instance this means 58 includes a capsule 60 containing a thermally responsive material. This material may be a substance that has a high coefiicient of thermal expansion or it may be a substance that will melt and expand at the temperature that is desired to actuate the valve 52. The capsule 60 may be disposed in a passage 62 that extends through one wall 64 of the manifold 12 into the cooling jacket 22. It has been found preferable to place this passage 62 adjacent the outlet 24. Thus the thermostat will be disposed in hot water flowing out of the engine thereby improving the accuracy of the thermostat. An annular collar may be provided around the capsule 60 to form a shoulder 68 which seats on the exterior of the manifold 12. A piston or plunger 70 may project from the top of the capsule 60 to move in an axial direction as the material expands and contracts.

In order to secure the thermostat 58 in position, a retainer 72 may be provided. The presentretainer- 72 comprises an inverted cup-shaped member 72Ythat is disposed over the capsule 69 and secured to the manifold 12 by'any suitable means. This retainer 72 may have a shoulder 74 that will engage the shoulder 68 andv compress it against the manifold 12. In order to seal. the coolant in the jacket 22, a gasket 76 may be placed on the manifold 12 to be compressedbetween the retainer 72 and the shoulder 68. Since the shoulder 68 does not move on the manifold 12 there will be no relatively movingparts in this seal, and consequently,v a hermitical seal will be provided between the thermostat 58 and the manifold 12 that will prevent the loss of any coolant.

An opening 77 may extend through the .top of the retainer 72 to allow the plunger 70 .to project therefrom.-

In order to transfer movement of. the plunger .70 to the butterfly valve 52, a bell crank'78 may be mounted on a bracket 80 projecting upwardly from the top of the retainer 72. One arm of the bellcrank v78 may rest on the plunger 70 while another arm is connected to a link 82. The link 82 may be connected'to a lever 84 projecting from the pin 53 supporting the valve 52. Thus as the material expands, the bell crank 78 will pivot on the bracket 80 and pull the valve 52 open. A spring 86 may be provided to oppose the thermostat 58 and thus retain the bell crank 78 incontact with the plunger 70.

It may thus be seen that a thermostat 58 has been pro-. vided which may be disposed in intimate heat exchanging relation with the liquid coolant. This-will permit an accurate sensingof the engine temperature and the thermostat may give an external indication of the engines temperature without permitting any fluid to escape from' the cooling system.

It is to be understood that, although the invention has been described with specific reference to a particular embodiment thereof, it is not to .be so limited since changes ing inwardly from one side of an engine to communicate with a cooling jacket in said engine, one end of said thermostatic means including a thermally expansive material, the opposite end of said thermostatic means including a plunger operatively connected to said material and reciprocably projecting therefrom, an annular collar disposed between said ends, said first end being disposed in said passage in heat exchanging relation with said jacket, and said collar being seated on said .side of said engine adjacent said passage.

2. Thermostatic means-mounted in a passage extending inwardly from one side of an-engine to communicate with a coolingjacket insaid engine, said thermostatic means comprising an annular shoulder, an end projecting axially from one side of said shoulder and including a material having a relatively high co-efficient of thermal expansion, the opposite end including a plunger operatively connected to said material and projecting from the other side of said shoulder to be movable in an axial direction, said first end being disposed in said passage and said shoulder being adapted to be secured against said side and a clamp secured to saidside of said engine for forcing said shoulder against saidside.

3. Thermostatic means mounted in a passage extending inwardly. from aside .of an engine to communicate with a cooling. jacket in said engine, one end of said thermostatic means. being disposed in said passage and including a thermally expansive material, a plungeroperatively connected to .said material and projecting .axiallytherefrom to formthe opposite :end of said .means, an annular collar disposed between said endsand being seated on said side of said engine, a clamp/ comprising. a cup-shaped member secured to. said engine, saidcup-shapedmember having an opening therethrough to permit said plunger to .project therefrom and alever mounted on said cup-shapedmemher .to engage said plunger and actuate a control linkage.

References-Cited in the file of this patent UNITED .STATES PATENTS 1,475,313 Newhard Nov.=27, 1923 1,824,789 Payne 1 Sept; 29, 1931 1,849,008 Hutchinson Mar. 8, 1932 2,123,347 Ware July 12, 1938 2,368,182 Vernet Jan. 30, 1945 2,694,415 Dillon Nov. 16, 1954 

